The Alpha Experiment
by julyheat
Summary: Amelia is summoned to 221B Baker Street to help with an experiment gone wrong. Sherlock managed to turn John into an Alpha and needed Amelia to administer the serum that would turn him back to normal. But John has his own idea of what he and Amelia can do instead. Basically PWP. John/OC. Enjoy!


**What time are you leaving your bakery today? SH**

Amelia was thrown off at the random text that she received from her older brother. Usually, Sherlock was not one to beat around the proverbial bush.

_I just have to wait until Jane gets here to finish training the new hires, so about 20 minutes. Why? AH_

**Both John and I need your immediate assistance. Come to Baker Street as soon as you can.-SH**

_Your degree of forthrightness is concerning. Why do you need my help? AH_

**This is definitely a situation where it is best revealed directly.-SH**

_Too hard to explain in 160 characters or less? AH_

**Yes.-SH**

John mentioned that Sherlock was especially excited about his new experiment that he was starting today. Amelia figured that it went wrong somehow and John needed help cleaning up the kitchen. Just last week, Sherlock managed to cover the entire flat with a layer of pink powder and instead of assisting in the subsequent scrubbing, he merely collapsed onto the couch and pondered where he went wrong. Amelia turned to Colin. "Sorry about that, a family situation is brewing."

About thirty minutes later, Amelia made her way up the stairs to 221B Baker Street. Judging by the sounds of John's shouts and the loud thumping, Sherlock really buggered up the experiment. Amelia slowly opened the door and peeked inside. Sherlock was seated calmly at the kitchen table, glass tubes filled with various liquids and powders surrounded him. John's voice could still be heard, though he was nowhere to be seen. Opening the door entirely, Amelia stepped into the flat. Sherlock finally looked up. "Ah, there you are. It seems there has been a bit of a hiccup in my experiment."

Sherlock's broad smile instantly made Amelia wary. The sounds of John's shouting seemed to be coming from Sherlock's room and the thumping noise was him pounding and kicking at the door. Now that she was closer, Amelia could make out the words that her boyfriend was shouting.

"Sherlock, let me out! You have no right to lock me in here. Sherlock!"

Amelia started towards Sherlock's room. "And this hiccup that you were mentioning required you to lock John in your room? What the hell happened?!"

"Amelia? Is that you, love? Sherlock's gone mental. Come let me out, baby, I need to see you." John's voice slowly went from irate to deep and nearly seductive.

Before Amelia could open the door, Sherlock blocked her. "I should really explain what happened before you open that door."

The doorknob twisted and jiggled as John tried to open the obviously locked door. "Sherlock, don't you dare keep her from me. She's mine, goddamnit! Amelia, don't listen to him. Love, you smell like you are anxious. Come in here so I can protect you."

Surprised at John's cursing and nearly bipolar shouts, Amelia followed Sherlock to the table. Studying the vials and cylinders, Amelia pressed Sherlock for answers. "Clearly, your experiment went wrong and whatever you had in that broken vial got into John's bloodstream. Judging by the threats he was making towards you and the desperation he demonstrated for me to come into that room, the solution had some strong hormones in it. He now sees you as the enemy and me as his…."

"Mate." Sherlock didn't even look up from his microscope. "As usual, you're able to figure out what happened without me having to stop and explain it. Have I mentioned that I'm happy that you aren't like any of the other imbeciles out there?"

"Multiple times, what do you mean, mate?"

As Sherlock began to mix two liquids together, eyes still focused on the task at hand, he explained. "Last time I was at the Yard, Anderson kept going on about some stupid fanfiction about me and John. Something about Alpha and Omegaverse. He was annoying me so, just as Donovan was entering the room, I quickly deduced that he and his wife reconciled and slept together the night before. Naturally, she got upset and Anderson scampered after her. But I was mildly interested in hearing more about this Alpha and Omega relationship. Mostly to assist with cases, you never know when an obsessed fan takes this work too seriously."

Amelia rolled her eyes and tried to block out the sounds of John's yelling. "This is all very interesting, Sherlock, but why don't you get to the point?"

"What I was _trying_ to get at, sister, was the interesting notion of having a dominant and submissive, almost animalistic nature of a relationship. Surely, it would be easy to recreate such a being. It's all in the hormones, which you already had brilliantly pointed out."

A migraine was slowly building around Amelia's temples. She leaned over the table, elbows on the one clean surface, and began to slowly rub at her forehead. "So out of sheer curiosity, you made a hormonal drug that reduces rational human beings into animalistic creatures?"

At Amelia's tone, Sherlock looked up. "Well I wasn't planning on using it! John came in to make a cuppa and somehow managed to bump the table, knocking over my sample. The vial inevitably broke and when John stepped back to get away from it, some glass cut his foot and the solution got into his bloodstream. The transformation was remarkably quick, though he did recognize me as another Alpha and immediately got defensive, hence, why he is locked in my room."

"And you plan on keeping him in there until it wears off?"

Sherlock look affronted. "Good lord, no! Could you imagine how long that would take? No, I merely made another hormonal shot that can counteract the effects of the Alpha solution. I need you to go in there and administer it."

As Sherlock held out the needle, Amelia backed away with her hands up. "Not a chance. This is your fault and you need to fix it."

"Don't be ridiculous, Amelia. He doesn't want me in there. If I try to enter, he will attack me. You've heard his pleas. Clearly he wants you in there. Now all you have to do is inject this serum into his arm."

Amelia was still not persuaded. "Why does he want me in there so badly then?"

Sherlock looked uncomfortable. "You slept over last night, remember? His scent is still on you and your scent is nearly everywhere. John recognizes you as his Omega."

"I'm his what?! Do you honestly think I have a submissive bone in my body?" Amelia could not remember the last time she was so offended.

Sherlock ignored Amelia's screech with an eye roll. "It has nothing to do with that, Amelia. John recognizes you as his mate and has an overwhelming urge to protect you. Since he is an Alpha, he naturally is assuming that you are his Omega. This will all be over quickly if you just take the serum and inject him."

Knowing that there was only one way to fix this problem, Amelia snatched the needle out of Sherlock's outstretched hand. "Fine, I'll do it. But the next time Anderson says something that piques your attention, it'd do well if you remind yourself that he is an outright idiot!"

Instead of walking into Sherlock's room from the kitchen, Amelia walked into the bathroom. She shut that door, but left it unlocked. John must have sensed Amelia's change in route because he quieted down and was standing at the door separating Sherlock's room from the bathroom. "Don't be afraid, darling, I would never hurt you."

Amelia unlocked the door and quickly walked inside. At first glance, nothing seemed out of the ordinary, aside from John standing in Sherlock's room. Once Amelia shut the door, John quickly wrapped his arms around her and pressed his face into her neck. "You aren't nervous at all, love, that's fantastic. The smell of your anxiety in the kitchen was putting me on edge. I just wanted to break through that door and make it all better."

John slid his hand down Amelia's arm until he felt the syringe in her hand. With a move that was too fast to process, he yanked it away and threw it on top of the wardrobe. Amelia cursed silently for not making sure that she had a spare. "John" she started.

"Call me Captain, I love it when you call me that." John moaned as he began to nip and kiss at Amelia's neck.

Amelia might have made a snarky comment if it hadn't been for the doctor's skilled mouth. "Captain," she corrected, ignoring his pleased moan. "I need that syringe back."

"No." John responded between his small bites. "Not yet, I'm too busy having fun."

Amelia temporarily lost coherent thought when John grazed his teeth over the scar that was just under her chin. "It's just that, oh god Captain, we can still have f-f-fuck, fun when you are in your right state of mind."

John chuckled darkly as he dragged his hands from Amelia's arms, down her torso, and squeezing her hips. "But I can't smell how I'm affecting you when I'm in my right state of mind. You're ready for me already, I can tell." He slowly started to sink to his knees, intending on tasting her arousal when he noticed a new scent at Amelia's right arm. Male. "What the fuck is this?"

He began to sniff at the offending smell. "Who were you with and why do you stink of him?"

Nothing killed a mood like a jealous Alpha, Amelia soon realized. She instantly started to run her hands through John's hair and calmly whispered "I was training my new barista, remember? I must have bumped into him while I was showing him the espresso machine. You know how small that area is."

A possessive growl was the only response she got. "Fine." She muttered as she pulled off her jumper. "See? The smell is gone."

"Not good enough." John shot out.

He pulled Amelia to the ground and covered her body with his. Fighting the urge to rut against his mate, John began to nuzzle at Amelia's neck and worked his way down the offending arm. "He needs to know that you belong to me. You're mine."

Forgetting about her task at hand, Amelia ran her nails up John's back. "He knows, love, don't worry. They'll all know that I'm yours."

"No they don't, not really. You have to tell them that you're taken. I want them to just be able to know when they look at you." John's voice was rough and slightly muffled as he worked his way to her stomach.

A glint of mischief shone in his eyes as he made his way back up to Amelia's throat. Lowering his mouth, John began to suck at her skin and smelled the wave of arousal that coursed through both of their bodies. Amelia moaned but tried to push him away. "Captain, I'm not a teenager. Love bites aren't nearly as acceptable on adults."

Frustrated, John bit down at where Amelia's neck met her shoulder. A hot streak ran from the where John bit her to the pit of her stomach as Amelia fought the urge to beg John to just take her now. "Trust me, love, I have a better idea."

John's hand travelled under Amelia's skirt as his fingers teased the edge of her stockings. "As long as it includes you screaming underneath me as I pound into you, I think I can compromise."

Amelia honestly tried to speak, she really did. But John's hands crept up to the apex of her thighs. She gasped and writhed at both the sensation and the look on John's face once he realized that Amelia was bare under her skirt. "Oh, baby." John moaned. "If you only knew what you are doing to me."

He brushed his thumb across Amelia's clit, stifling her cry of pleasure with his mouth. Circling over the bundle of nerves, John used his other hand to grab Amelia's wrists and pinning them over her head. Without breaking his rhythm, John sank a finger into Amelia and marveled at how wet she already was. Amelia arched her back and started to lift her hips, desperate for more friction. John withdrew his hand and before Amelia could let out a disappointed whimper, stuck his finger into her mouth. "Taste yourself, taste how aroused you are."

At this point, Amelia was all sensation. Wrapping her tongue around John's thick finger, she began to suck. Amelia never had much experience with her own taste, but was pleasantly surprised to realized that it was not that bad, even a little spicy. While her usual sex life with John was extraordinarily satisfying, there was something about how John managed to dominate her body while thoroughly pleasuring her.

It was so fucking hot.

John pushed a second finger into Amelia's mouth, which she happily accepted. His eyes were hooded as he watched Amelia massaged his fingers with her tongue and sucked them at the same time. "Tell me you don't want it like this, that I am not satisfying your needs."

He took out his two fingers to let her answer. Amelia fisted her hands in her hair, already missing the sensation. She knew that she needed to give John the second serum and that it would be best for everyone if he went back to his usual loving self. But she couldn't bring herself to stop him. "I can't. This feels amazing, don't stop."

His response was thrusting his fingers back into Amelia's heat. He sought out her G-spot as his thumb relentlessly massaged her clit. "Don't hold back, love, show me how good it feels."

Amelia wanted nothing more than to scream in ecstasy. However, her stupid brain decided to start working again and reminded her that her brother was in the next room. Almost as if John read her mind, he pumped his fingers faster and said "Don't worry, Sherlock left right when you were walking in here." At Amelia's confused look, John chuckled. "It appears that in addition to my sense of smell, the drug also enhanced my hearing."

With his pinky, John traced the hole to Amelia's arse before quickly sinking it past the ring of muscle. Amelia winced at the burning sensation before was replaced by a molten layer to her pleasure. "Oh fuck, oh god, Captain!"

John pulled himself up and watched Amelia. Her arms were still pinned above her head, which was thrown back. Her mouth was bright red and was in the shape of an 'O.' John loved the unabashed cries that were pouring out at that moment. Amelia's hips were grinding against his hand, her juices flowing down his wrist. "So about that compromise. I'm willing to take the second injection because we all know that I can't exist in this day and age acting like a possessive Neanderthal. But it will not happen until I take you so hard that you won't be walking straight for at least a week. Deal?"

"Deal." Amelia gasped. "But not in here, Sherlock would kill us."

Lowering himself down, John gently released Amelia's arms and eased his other hand out from inside her. "I can see your point."

They kissed deeply before standing up. John noticed that Amelia was slightly unsteady on her feet and wrapped an arm around her. Before leaving the room, Amelia reached up over the wardrobe and retrieved the syringe. As soon as they crossed the threshold into the bathroom, John slammed the door shut and pressed Amelia's body to the wood. Dropping to his knees, John pushed Amelia's skirt over her hips and eagerly began to lick and suck her clit. After getting so wound up previously, it wasn't long before Amelia could feel heat pooling at the base of her stomach and her legs began to shake. John had to hold Amelia up by the hips as she came loudly, her cries echoing around the bathroom. "Oh yes, yes! Fuck, Captain!"

John was on his feet, pulling Amelia out of the bathroom and up the stairs to his bedroom before she even had time to catch her breath. He practically ran over to his bed and pushed Amelia onto the mattress. Amelia could only hold onto the comforter as John ripped her skirt and bra off. As soon as she was naked, Amelia sat up and started pulling at John's shirt. "I want to see all of you."

John leaned back and let Amelia properly take his t-shirt off. He moaned at the sensation of her warm hands caressing his chest and stomach. Amelia's mouth soon followed as she spun John around and laid him onto the bed. Using her lips, tongue, and teeth, she worked her way down to John's waistband of his trousers. She made small work of undoing the button and zipper and pulled down both the trousers and his pants. John's cock was hard and leaking precum. Wrapping her hand around his manhood, Amelia stroked John, running her thumb over the head and spreading the precum around. John sat up and took Amelia's breasts in his hands, pinching her nipples before replacing one of his hands with his mouth. "Slow down, baby, I'm too close." He murmured before biting lightly onto her hardened nipple.

He waited until Amelia moved her hand from around his cock before rolling her onto her back. As John positioned himself between Amelia's legs, she moved her hand to the nightstand, where John kept the condoms. Ripping the wrapper open with her teeth, Amelia put the condom into her mouth and leaned over. With her hands on John's hips, Amelia slowly unrolled the condom over John's leaking member. John's fingers weaved themselves into her hair as he struggled not to thrust into Amelia's warm mouth. Once the condom was covering John's cock, Amelia kept sucking John off. She took him deep and hummed her pleasure. John arched his back as the vibrations on his shaft nearly pushed him over the edge. "Amelia, please. I want to cum inside you." His voice was rough and laced with need.

Amelia released his cock with a loud pop before giving John a cheeky smile. She laid back down and wrapped her legs around his waist. "So take me, Captain."

John did not waste any time. With a thrust of his hips, he buried his dick deep in Amelia. Both of them were too caught up in their shared arousal to move slowly. John pounded into Amelia as he tilted her hips up and moved her legs from his shoulders. Amelia cried out at the change in the angle as John's hips ground against her clit. She could only gasp and shout incoherent words as her body burned with desire. John continued to roll her nipples between his fingers, pulling occasionally. "That's right, sweetheart, I want you to come apart again for me. Fuck, I'm so close, cum for me."

At John's words, Amelia's vision went white. The heat that was centering in her stomach shot out to the rest of her body as she began to shake. John relentlessly fucked Amelia through her orgasm as she screamed. Her muscles contracted and at the tightening sensation, John felt himself explode inside of Amelia. "Fuck yes! Oh my god!"

Exhausted, John collapsed on top of Amelia. Wrapping his arms around her again, John slid his softening cock out and nuzzled against her neck. "Mine." He whispered.

Amelia drew symbols onto John's back and hummed with contentment. "Yes, yours. I wish you would believe that."

"I do. It's just the other men who think I don't notice when they look at you." John's grip tightened. "Can I have that shot now? I hate feeling this jealous of them."

He hissed lightly as Amelia stuck the syringe into his arm. She gave him a sheepish look. "Sorry about that, I didn't know how long I had before you changed your mind."

"S'alright, I would have done the same." John yawned and slid off Amelia, settling her head onto his chest. "I hope this works as quickly as the other one did."

"Mmmm, me too." Amelia's eyes grew heavy as she drifted off to sleep.

John watched Amelia for a few minutes. "Though I really do wish you knew how you make me feel."

Sighing, John allowed himself to fall asleep as well.


End file.
